1. Volume 67, Issue 2, Pages 432-442 (February 2005)
Differential expression of Cux-1 and p21 in polycystic kidneys from Pkd1 null and cpk mice 
Madhulika Sharma, Jennifer G. Brantley, Neal I. Alcalay, Jing Zhou, Engela Heystek, Robin L. Maser, Gregory B. Vanden Heuvel 
Kidney International 
Volume 67, Issue 2, Pages (February 2005)
DOI: /j x
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2. Figure 1
Cux-1 is ectopically expressed in kidneys isolated from Pkd1 null mice. (A) Cux-1 expression is restricted to the nephrogenic zone (NZ) in late embryonic wild-type kidneys. (B) Kidneys isolated from embryonic day 19 Pkd1 null mice reveal ectopic expression of Cux-1 in both normal tubules (arrow) and in cells lining the cysts (original magnification 400×; bar, 50 μm).
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3. Figure 2
Coexpression of Cux-1 and proliferating cell nuclear antigen (PCNA) in the cysts of kidneys from Pkd1 null mice. Early- [embryonic day 15 (E15)] and late- (E19) stage polycystic kidneys were evaluated for expression of Cux-1 and PCNA. Low (A to D) and high (E to H) magnification images of kidneys isolated from E15 Pkd1 null mice following labeling for Cux-1 (B and F) and PCNA (C and G) expression. At early stages of cystogenesis (A to H), Cux-1 was ectopically expressed in maturing tubules and in cysts (B and F). PCNA labeling (C and G) showed proliferating cells lining the cysts, but not in all cells. (D) Merged image (B and C) [boxed region is shown in (H)]. (H) The merged Cux-1 and PCNA images showed colocalization in cyst lining cells (arrows), but not in some tubules that were positive for Cux-1 only (*). (I to P) At late stages of cystogenesis, Cux-1 expression remained elevated in maturing tubules and cysts (J and N), and colocalized with PCNA throughout the cystic kidneys, both in the nephrogenic zone and in cells lining the cysts (* and arrows). Boxed region in (L) is shown at higher magnification in (P) [original magnification (A to D, I to L) 200×; bar, 100 μm; (E to H, M to P) 400×; bar, 50 μm].
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4. Figure 3
Reduced expression of p21 in kidneys from Pkd1 null mice. Kidneys isolate from embryonic day 19 (E19) Pkd1 null mice were labeled with antibodies directed against Cux-1 and p21. (A) Cux-1 is ectopically expressed in cyst lining cells. (B) p21 is not expressed in the in the tubules or cysts of Pkd1 null kidneys. (C) Since p21 is not expressed in Pkd1 null kidneys, there is no overlap in the merged image (original magnification 200×; bar, 100 μm).
Kidney International  , DOI: ( /j x)
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5. Figure 4
Reduced expression of p27 in kidneys from E19 Pkd1 null mice. Embryonic day 15 (E15) (A to D) and E19 (E to H) kidneys isolated from wild-type (A, B, E, F) and Pkd1 null (C, D, G, H) mice were labeled with an antibody directed against p27. (B and F) p27 is not expressed in the nephrogenic zone of kidneys isolated from wild-type E19 mice, but is up-regulated in maturing glomeruli (arrow) and tubules. p27 is expressed at similar levels to wild-type in cystic kidneys isolated from E15 Pkd1 null mice (D), but p27 expression is reduced in maturing tubules of cystic kidneys isolated from E19 Pkd1 null mice. p27 expression was observed in maturing glomeruli of both wild-type and cystic kidneys (arrows) (original magnification 100×; bar, 200 μm).
Kidney International  , DOI: ( /j x)
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6. Figure 5
Differential expression of Cux-1 and proliferating cell nuclear antigen (PCNA) in the cysts of 7-day-old and 20-day-old cpk kidneys. Early- (7-day-old) and late- (20-day-old) stage polycystic kidneys from cpk mice were labeled with antibodies for Cux-1 (B, F, J, N) and PCNA (C, G, K, O). (A to H) In kidneys from 7-day-old cpk mice, Cux-1 and PCNA colocalize in the nephrogenic zone (D), but not in the medulla where cysts are forming (H). Cells lining the cysts are PCNA positive (G), while Cux-1 expression is restricted to interstitial cells (F). (I to P) In kidneys from 20-day-old cpk mice, Cux-1 is ectopically expressed in cells lining the cysts (J, arrow) and (N, arrowhead). While some cells lining the cysts are PCNA positive (O, arrow), most are not. Merged image (P) shows that Cux-1 is expressed in most of the cyst lining cells, but only a few are also positive for PCNA (arrow) [original magnification (A to D) 50×; bar, 500 μm; (E to L) 200×; bar, 100 μm; (M to P) 400×; bar, 50 μm).
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7. Figure 6
p21 is ectopically expressed in the cysts of kidneys from 7- and 9-day-old cpk mice. (A to D) Kidneys from 7-day-old wild-type mice were labeled with antibodies for Cux-1 (B) and p21 (C). Cux-1 is expressed primarily in interstitial cells, while p21 expression is not detected. (E to H) Kidneys from 7-day-old cpk mice were labeled with antibodies for Cux-1 (F) and p21 (G). Cux-1 is expressed primarily in interstitial cells. In contrast to wild-type, p21 expression is up-regulated in cells lining the cysts (G). Cux-1 and p21 do not colocalize (H). (I to L) Cux-1 and p21 expression in kidneys from 9-day-old cpk mice localizes similarly to kidney from 7-day-old cpk mice. Cux-1 and p21 do not colocalize (L) (original magnification 200×; bar, 100 μm).
Kidney International  , DOI: ( /j x)
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8. Figure 7
Colocalization of Cux-1 and p21 in kidneys from 20-day-old cpk mice. Kidneys from 20-day-old cpk mice were labeled with antibodies for Cux-1 and p21. Cux-1 (A) and p21 (B) are ectopically expressed in both cyst lining cells and in normal appearing tubule epithelium (arrow). In some tubules, Cux-1 and p21 expression colocalize (C) (original magnification 400×; bar, 50 μm).
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9. Figure 8
Ectopic expression of p21 and p27 protein in cpk kidneys. Thirty micrograms of nuclear extract prepared from kidneys from 16- and 21-day-old wild type (WT) and cpk mice was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to nitrocellulose membranes. (A) The presence of p21 protein was detected by using a monoclonal antibody to p21. p21 was detected at high levels in cpk kidneys, but not in age-matched wild-type kidneys. (B) Similarly, p27 was detected at high levels in cpk kidneys, but not in age-matched wild-type kidneys. Equal loading of protein was confirmed by Ponceau S staining. Molecular weight standards are shown on right.
Kidney International  , DOI: ( /j x)
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10. Figure 9
Increased apoptosis in late stage cpk kidneys. (A) The terminal deoxynucleotidal transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) method was used to identify apoptotic cells in early (B and H) and late (E and K) stages of cystogenesis in kidneys from Pkd1 null (B and E) and cpk (H and K) mice. (B) Apoptotic cells were observed primarily in the nephrogenic zone of the kidneys from embryonic day 15 (E15) Pkd1 null mice, with few apoptotic cells in the cysts (*). (C) The TUNEL staining was merged with the nuclear stain (DAPI) (A) to identify TUNEL-positive cells. (D to F) Few apoptotic cells are observed among the cyst lining cells in the kidneys from E19 Pkd1 null mice (arrow). (G to I) Similarly, there are few apoptotic cells found among the cyst lining cells in the kidneys from 7-day-old cpk mice (arrow). (J to L) In contrast, numerous TUNEL-positive cells are observed among the cells lining the cysts in the kidneys from 20-day-old cpk mice. The merged TUNEL and DAPI image (L) shows that TUNEL-positive staining corresponds to nuclei (original magnification 200×; bar, 100 μm).
Kidney International  , DOI: ( /j x)
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11. Figure 10
Colocalization of Cux-1 and terminal deoxynucleotidal transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) cyst lining cells of late-stage cpk kidneys. (A) To determine whether Cux-1–positive cells were also apoptotic, sections of kidneys from 20-day-old cpk mice were labeled with antibodies directed against Cux-1, followed by TUNEL labeling. (B) Cux-1 was ectopically expressed in many of the cyst lining cells (arrows). (C) Apoptotic cells were observed among many of the cyst lining cells (arrows). (D) The merged image shows that most of the cyst lining cells were both Cux-1 and TUNEL-positive (arrow), while most of the interstitial cells only expressed Cux-1 (arrowheads) (original magnification 400×; bar, 50 μm).
Kidney International  , DOI: ( /j x)
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